DUBAI, Feb 17 (Reuters) - Japan's SoftBank Group has provided nearly half of the cash for Abu Dhabi's state investor Mubadala Investment Co's new $400 million fund investing in European start-ups, a source familiar with the matter said.

Mubadala, which has committed to invest $15 billion in SoftBank's Vision Fund, last week announced that Mubadala Ventures was planning to launch a $400 million technology-focused European fund this year.

Softbank and Mubadala declined to comment on the story, first reported by the Financial Times earlier on Monday.

The European venture fund, which has already made a few undisclosed investments, will be run from a new office in London, the FT said.

In late 2017 Mubadala had announced the setting up of a venture capital arm that it said will oversee an early growth fund set up with Japan’s SoftBank. The ventures team was to be based in San Francisco, its first office in the United States.

Abu Dhabi-based Mubadala Investment manages a $225 billion portfolio.

Reporting by Saeed Azhar in Dubai and Sam Nussey in Tokyo
Additional reporting by Ishita Chigilli Palli in Bengaluru
Editing by David Goodman